<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			//js中定义变量var
			var x=10;
			var y=20;
			
			console.log(x+y);
			var a=10,b=20;
			console.log(a*b);
			
			var x=100;//java中局部变量不能重复定义，JavaScript不会报错
			console.log(x);//变量再次声明，前面声明的值就会被覆盖
			
			var x="adg";
			console.log(x);
			console.log(typeof(x));
		</script>
	</head>
	<body>
	</body>
</html>
